Hi,
I want to pass destinationpath as MemoryStream to VectorLayer.Convert for further use. If there is any option can you please share chunk of code.
I want to execute below code
var outputStream = new MemoryStream();
VectorLayer.Convert(shapefilePath, Drivers.Shapefile, outputStream , Drivers.GeoJson);
Yes, you can pass a MemoryStream as the destination path to the VectorLayer.Convert method. Below is a code snippet demonstrating how to achieve this:
using System;
using System.IO;
using Aspose.Gis;
using Aspose.Gis.Layers;
public class Example
{
public static void Main()
{
string shapefilePath = "path/to/your/shapefile.shp"; // Specify your shapefile path
using (var outputStream = new MemoryStream())
{
// Convert the shapefile to GeoJson and write to the MemoryStream
VectorLayer.Convert(shapefilePath, Drivers.Shapefile, outputStream, Drivers.GeoJson);
// Optionally, you can read the content from the MemoryStream
string geoJsonOutput = System.Text.Encoding.UTF8.GetString(outputStream.ToArray());
Console.WriteLine(geoJsonOutput);
}
}
}
In this example, the VectorLayer.Convert method is used to convert a shapefile to GeoJson format, and the output is written to a MemoryStream. After the conversion, you can read the contents of the MemoryStream as needed. Make sure to replace "path/to/your/shapefile.shp" with the actual path to your shapefile.
This approach allows you to handle the output in memory without needing to write it to a physical file on disk.
Above chunk of code is not working. I am getting error 'cannot convert from System.IO.MemoryStream to string. For reference please see attached, screen shot.
Error.png (226.8 KB)
@naeem.akram
Good day. I apologize, we are still testing our AI agent for quick answers and sometimes it turns out that the answers are not accurate. In any case, it is suggested that team members review the thread and leave a comment.
In your case, a working version of the code would be as follows:
string shapefilePath = "D:\\SomePath\\shapefile.shp"; // Specify your shapefile path
using (var outputStream = new MemoryStream())
{
// Convert the shapefile to GeoJson and write to the MemoryStream
VectorLayer.Convert(AbstractPath.FromLocalPath(shapefilePath), Drivers.Shapefile, AbstractPath.FromStream(outputStream), Drivers.GeoJson);
// Optionally, you can read the content from the MemoryStream
string geoJsonOutput = System.Text.Encoding.UTF8.GetString(outputStream.ToArray());
Console.WriteLine(geoJsonOutput);
}
@roman.charnashei
Thank you very much. I am facing another error like I want to convert file to memory stream for further actions in same way I want to read file from memory stream rather . For example in below cope I have opened and copied file to memory stream and then passing memory stream as input path but I am getting error ‘.SHX file is missing’ although I am using .shp file as input
string dataDir = RunExamples.GetDataDir();
string shapefilePath = dataDir + “InputShapeFile.shp”;
string jsonPath = dataDir + “output_out.json”;
MemoryStream ms = new MemoryStream();
using (FileStream file = new FileStream(shapefilePath, FileMode.Open, FileAccess.Read))
file.CopyTo(ms);
//ExStart: ConvertShapeFileToGeoJSON
//VectorLayer.Convert(shapefilePath, Drivers.Shapefile, AbstractPath.FromStream(cellsStream), Drivers.GeoJson);
using (var outputStream = new MemoryStream())
{
// Convert the shapefile to GeoJson and write to the MemoryStream
VectorLayer.Convert(AbstractPath.FromStream(ms), Drivers.Shapefile, AbstractPath.FromStream(outputStream), Drivers.GeoJson);
// Optionally, you can read the content from the MemoryStream
string geoJsonOutput = System.Text.Encoding.UTF8.GetString(outputStream.ToArray());
Console.WriteLine(geoJsonOutput);
}
For reference please find attached, error screen shot.
Error.png (384.6 KB)
@naeem.akram
Good day. Yes, your problem is related to the fact that reading a .shp file assumes that there are a number of related files nearby. But you have only one .shp file read into memory in a vacuum and the library can’t find the neighboring files.
string shapefilePath = "d:\\shapefile\\point.shp";
string outputFile = "output_out.json";
using var memory = new MemoryStream();
using (var inputLayer = VectorLayer.Open(shapefilePath, Drivers.Shapefile))
{
// make some manipulation with features if needed
inputLayer.SaveTo(AbstractPath.FromStream(memory), Drivers.GeoJson);
}
string geoJsonOutput = System.Text.Encoding.UTF8.GetString(memory.ToArray());
Console.WriteLine(geoJsonOutput);
File.WriteAllText(outputFile, geoJsonOutput);
This code will work if you have data located in files on physical storage.
There is a more complicated variant in case you have all your source data in memory. Now I will prepare an example and post it here.
Sorry, I don’t have data located in files on physical storage. I have all source data in memory so please share sample code for it.
@naeem.akram
Unfortunately at the current stage of implementation of the library we need to take additional actions, namely to implement a special MultiStreamPath class, here is the code:
public class MultiStreamPath : AbstractPath, IDisposable
{
private readonly string _entryName;
private readonly Dictionary<string, Stream> _storage;
private readonly List<Stream> _streams = new List<Stream>();
public MultiStreamPath(string entryName, Dictionary<string, Stream> storage)
{
_storage = storage;
_entryName = entryName;
}
public override string Location => this._entryName;
public override char Separator => '/';
public override bool IsFile()
{
// In our terms, if there is a entry on our stream list, we return true.
return _storage.ContainsKey(_entryName);
}
public override void Delete()
{
_storage.Remove(_entryName);
}
public override Stream Open(FileAccess access)
{
var stream = _storage[_entryName];
var openedStream = AbstractPath.FromStream(stream).Open(access);
_streams.Add(openedStream);
return openedStream;
}
public override IEnumerable<AbstractPath> ListDirectory()
{
return _storage.Select(item => new MultiStreamPath(item.Key, _storage));
}
public void Dispose()
{
foreach (var stream in _streams)
{
stream?.Dispose();
}
}
protected override AbstractPath WithLocation(string newLocation)
{
return new MultiStreamPath(newLocation, _storage);
}
}
And then use it as follows:
static void ThirdWay()
{
string geoJsonOutput;
var folder = "d:\\shapefile";
var outputFile = "output_out.json";
var storage = new Dictionary<string, Stream>
{
{ "point.shp", new FileStream(Path.Combine(folder, "point.shp"), FileMode.Open) },
{ "point.dbf", new FileStream(Path.Combine(folder, "point.dbf"), FileMode.Open) },
{ "point.shx", new FileStream(Path.Combine(folder, "point.shx"), FileMode.Open) }
};
using (var multiStreamPath = new MultiStreamPath("point.shp", storage))
using (var inputLayer = Drivers.Shapefile.OpenLayer(multiStreamPath))
using (var memoryResult = new MemoryStream())
{
// make some manipulation with features if needed
inputLayer.SaveTo(AbstractPath.FromStream(memoryResult), Drivers.GeoJson);
geoJsonOutput = System.Text.Encoding.UTF8.GetString(memoryResult.ToArray());
}
File.WriteAllText(outputFile, geoJsonOutput);
}
Sorry to bother you again.
Again this code using local path of file. Forget about file path we just have data in memory stream and have to read this data from memory stream like in all other Aspose libraries (Aspose.Words, Aspose.Cells, Aspose.Pdf etc) we can load document either from local file path or from memory stream.
@naeem.akram
Of course that’s what I meant. In the dictionary value is Stream.
Here is an example of reading purely from memory:
[HttpPost("files-test")]
public IActionResult Converter([FromForm] IEnumerable<IFormFile> files)
{
var storage = files.ToDictionary(x => x.FileName, x => x.OpenReadStream());
var firstFile = storage.Keys.Single(x => x.EndsWith(".shp"));
using (var multiStreamPath = new MultiStreamPath(firstFile, storage))
using (var inputLayer = Drivers.Shapefile.OpenLayer(multiStreamPath))
using (var memoryResult = new MemoryStream())
{
// make some manipulation with features if needed
inputLayer.SaveTo(AbstractPath.FromStream(memoryResult), Drivers.GeoJson);
var geoJsonOutput = System.Text.Encoding.UTF8.GetString(memoryResult.ToArray());
Debug.WriteLine(geoJsonOutput);
}
return Ok();
}